Method and apparatus for drying and cooling tobacco



June 24, 1941'. R. v. CRAGGS METHOD AND APPARATUS FOR DRYING AND COOLING TOBACCO Filed May 20, 1937 e Sheets-Sheet 1 Fllll ANN mm INVENTOR 'ROSS V.CRAGGS ATTORNEY June 24, 1941. R. v. CRAGGS 2,246,914 METHCD AND APPARATUS FOR DRYING AND COOLING TOBACCO Filed May 20, 1957 6 Sheets-Sheet 2 PIC-3.3

INVENTOR R0 SS V. CRAGG S ATTORNEY June 24, 1941. R. v. CRAGGS METHOD AND APPARATUS FOR DRYING AND COOLING TQBACCO Filed May 20, 1937 6 Sheets-Sheet 3 \w T \w W G 5m mm v w(||\ (L mm (Q m m HHHMHMWMHM \n n g l I 1 I l K. ww w l NM,

$1 7 Q m N H Q Q J aw I- \wfq J \N. NW MN MAUI INVENTOR ROSS v. CRAGGS A ORNEY June 24, 1941. R. v. CRAGGS METHOD AND APPARATUS FOR DRYING AND COOLING TOBACCO Filed May 20, 1937 6 Sheets-Sheet 4 Q%\ Aw ww km s G G M W m R ES 0 VS 1/ T mm m Y B June 24, 1941. R. v. CRAGGS METHOD AND APPARATUS FOR DRYING AND COOLING TOBACCO Filed May 20, 1937 6 Sheets-Sheet 5 INVENTOR ROSS V.CRAGG$ ATTORNEY June 24, 1941. R. v. CRAGGS METHOD AND APPARATUS FOR DRYING AND COOLING TOBACCO Filed May 20, 1937 6 Sheets-Sheet 6 INVENTOR ROSS V. CRAGGS BY y ATTORNEY Patented June 24, 1941 METHOD AND APPARATUS FOR DRYING AND COOLING TOBACCO Ross V. Craggs, Brooklyn, N. Y., assignor to American Machine & Foundry Company, a corporation of New Jersey Application May 20, 1937, Serial No. 143,699

18 Claims.

This inventiorfrelates to an improved method and apparatus for cooling and drying tobacco in which the tobacco is dried, conditioned and cooled ready for use in cigarette making machines.

Heretofore, shredded tobacco was dried in revolving steam heated drums or cylinders wherein the tobacco was tumbled over and over to secure an intimate contact of all portions of the tobacco mass with the hot surface of the drum. In the operation of these drums, portions of the tobacco would at times adhere thereto and be burned or scorched. An important object of the invention, therefore, is to avoid the stated disadvantage of such driers, and with this end in view the shredded tobacco is dried in a current of warm air.

In the case of cigarette tobacco, a guillotine cutter is generally employed to separate slabs or slices from a compressed mass of tobacco. wherefore the shreds thereof should be loosened to assure eifective drying. It is a further object of the invention, therefore, to open or loosen the slabs or slices prior to their delivery to the drier. With this end in view, a suitable form of opening mechanism is illustrated herein, but it will be understood that other suitable constructions may be employed.

In the illustrated embodiment of the invention the drier comprises an enclosed chamber having a series of vibrating sieves or tables, one delivering to the other, to pass the tobacco through the chamber. At one end tobacco is delivered through an inlet valve to the uppermost sieve. The vibrating motion of the sieve, which is lengthwise in direction, feeds the tobacco over the edge of the first sieve onto a shaker table which deposits upon the next sieve. Each sieve has perforations of about /2 mm. diameter for passing heated air without losing tobacco. As the tobacco is delivered from one sieve to the other, it is tumbled over more or less, which has been found important because it insures against.

the bottom of the layer being drier than the top. Air enters the bottom of the chamber after first passing through a steam heated radiator. and the warm air is drawn out of the top, which carries the air upwardly through the tobacco on I next table more uniformly. At the opposite endof the chamber from which the tobacco is de livered there is provided a partition, and into the compartment so formed cold air is admitted for the purpose of cooling the tobacco.

From what has been said, it will be seen that there is uniform drying without danger of contaptrwith steampipes and without the rough tumbling employed in present machines of this type, which tends to break up the shreds and create "shorts. Moreover, a flufly condition and uniform coloring are maintained due to the way the tobacco is fed and turned over. Control of the drying may be efiected by controlling the flow of air through the agency of a variable humidostat within the drier connected to a shutter in the air intake. Drying, dressing and cooling in the same unit and with the same handling of the tobacco are attained, including breaking up of lumps so that no additional operation is needed for this purpose.

The present construction is believed to accomplish its duty in a better manner than the three machines necessary at the present time. Of these, the rotary drying machine circulates the tobacco in direct contact with the steam heated elements and tends to destroy the oil secretion responsible for the desired flavor and aroma. Then when tobacco is discharged into the cooling machine, the tobacco mass is not properly and sufllciently cooled and tends to egglomerate and form a sticky mass when stored, thereby necessitating an additional machine comprising a rotary drum provided with vanes, which redresses the tobacco-before it is ready to be used in a cigarette making machine.

In the accompanying drawings, which form a part of this specification and in which like characters of reference indicate the same or like parts:

Fig, lis a side view of the drying and cooling machine;

Fig. 2 is a sectional end elevation taken on line 2-2 of Fig. 1, showing the manner of mounting the vibrating members;

Fig. 3 is a schematic plan view showing the drying and cooling machine used in connection with a tobacco shredder and tobacco slab openingmachine;

Fig. 4 is an end view of the tobacco slab openingmachine;

Fig. 5 is a side elevation of the same;

Fig. 6 is a side view showing the conveyor which delivers the tobacco from theslab opening machine to the distributor directing the same iililtio1 an inlet valve of the drying and cooling mac e;'- a

Fig. 7 is an end elevation of the same;

Fig. 8 is a side elevation of the shaker tables which convey the tobacco from-one sieve to the other through the drying chamber;

Fig. 9 is an end elevation of the same;

Fig. 10 is a plan view taken from line lit-I9 of Fig. 8, showing a portion of the toothed edge provided on the shaker plates.

Fig. 11 is a detail view, partially in section, showing the automatic shutter and associated parts' for admitting cool air to the air intake to regulate the air temperature.

Referring to the drawings, the tobacco leaves are placed in a tobacco shredding machine C of well known construction (Fig. 3) wherein the leaves are compressed to a more or less solid column fromthe forward end of which slabs or slices of the thickness requisite to produce the desired thickness of shreds are cut. The slabs fall on to a conveyor A and are carried to the slab opening mechanism in which they are rolled, first in a counterclockwise direction, and then. in a clockwise direction, thereby loosening the solid slab and producing a loose, more or less cylindrioally shaped plug. This formed plug emerges from the slab opening device and falls on to a conveyor belt B which transports the same on to a conveyor E delivering to the drying and cooling machine D in which the tobacco is dried and cooled. The conditioned tobacco is finally discharged through an outlet valve into a truck T wherein the shredded tobacco is removed to the cigarette making machines or to storage bins as desired.

The opening mechanism (Figs. 4 and 5) consists of an upper rotating drum l5 turning in a counter-clockwise direction and a lower rotating drum l8 turning in the opposite direction, said drums being made of any suitable material, such as wood, metal or composition, plain or covered with fabric, as indicated by the hatching in Fig. 4, and mounted on shafts l1 and I8 respectively, supported in bearings of the upright frames l9 and 28. A tie plate 2! carried by frames l9 and 29 supports a motor 22' equipped with a sprocket 23 driving a chain 24 running over a sprocket 25 fixed on end of shaft l1. The other end of shaft I1 is provided with a gear 28 in mesh with a gear 21 fixed on shaft l8, the opposite end of shaft l8 carrying a bevel gear 28 driving a bevel gear 29 attached to shaft 39 supported in a bracket 31 fastened to the frame l9. Shaft 39 also carries a sprocket 32 driving a chain 33 running over a sprocket 34 fixed on shaft 35. The pulley 38 fastened on shaft is thereby rotated in the proper direction to drive the conveyor belt B running over an idler pulley 31 loosely mounted on a shaft 38. Shafts 35 and 38 are supported in brackets 39 and 49 respectively, attached to the bed 4| of the mechanism. Gear 21 drives a pinion 42 mounted on a stud 48 supported in frame 29, said pinion having fastened thereto a sprocket 44 driving a chain 45 running over a sprocket 46 whereby motion is imparted to shaft 41 and pulley 49, thereby driving conveyor belt A.

Each cut tobacco slab is delivered by conveyor A on to the drum 1 5 and carried against an apron 49 which is yieldingly held in contact with said drum and nips the leading end of the slab of tobacco and thereupon rolls the same into a cylindrically shaped plug. This rolling action tends to open or loosen the compressed shreds of tobacco. On leaving drum I5 and apron 49, the rolled plug of tobacco drops on to the lower drum l8 which turns in the opposite direction and is also provided with a similar apron 49 which is arranged on the opposite side of drum l8 and coacts with its drum '18 to roll the plug in the opposite direction, whereby it is more considerably loosened. The plug, on leaving the lower drum i8, drops onto the conveyor B which transports the same to a conveyor E delivering to the inlet of the drying and cooling mechanism.

At its upper end, each apron 49 is looped around a cross rod 59 supported in arms 5| adjustably mounted on a shaft 82 supported by frames [9 and 20. An arm 88 attached to one end of each shaft 52 provides means for changing the position of arms 5| and aprons 49 relatively to the drums l5 and IS. The lower end of. each apron 49 is looped around a. cross rod 54 supported at its ends in arms 55 loosely mounted on shaft 52, the other end of arms 55 being fastened to the springs 58 connected to adjusting screws 51 carried by lugs 58 of arms 5|. In the described manner, each of the aprons 49 may be adjusted for longer or shorter contact of tobacco between the drum and apron and for tight or loose tension to suit the condition of the tobacco in order to obtain best results. Holders 55a, attached to frames l9 and 29, are equipped with adjustable stop members or screws 55b resting against arms 55 and thereby controlling the movement of said arms in one direction and also limiting the pulling action of springs 58. With this arrangement either apron 49 can be-adiusted to fulfill its duties of rolling the slab of tobacco, and it may be noted that if the apron is too tight about its drum it will have a tendency to break the slab of tobacco rather than roll it. A beater driven from shaft 35 by a belt drive 8|, is located below the lower loop of conveyor 3' and acts to vibrate and thereby remove dust or loose tobacco shreds from the same.

The loosely rolled plugs deposited upon conveyor E are transported upwardly, and on arriv-' ing at the peak of the conveyor, by the momentum of the same, are hurled against a deflector (Figs. 6 and-'1). The plugs are thus loosened into shreds and fall upon an oscillating platform 88 which further tends to spread the tobacco lumps, directing and distributing the same across the entire extent of the inlet valve 81 of the drying and cooling machine, in order to deliver an even mat of tobacco to the uppermost vibrating screen to be presently described.

A motor shaft 58 driven from motor 69 is equipped with a pinion 19 and a sprocket 1| (Fig. 7), the latter driving a chain 12 running over a sprocket 13 fastened on shaft 14 (Fig. 6). Shaft 14 is supported by pedestals 1i and 18 attached to bed-plate 11, a sprocket 18 also fastened on said shaft driving a chain 19 running over sprocket 89 fastened to shaft 81. A- pulley 82 on shaft 8! drives a conveyor- E running over an idler pulley 88 (Fig. 5). Pinion 18 drives a gear 84 loosely mounted on a stud 85 supported in a bearing of bracket 88 which is fastened to plate 11. To the gear 84 is fastened a bevel gear 81 meshing with a bevel gear 88 carried by an upright shaft 89 supported in bearings of bracket 88. e upper end of shaft 88 is provided with a crank-disk 99 carrying-a crank-pin 8| connected to oneend'of a link 92 which is pivotally mounted at its other end in a stud 93 fastened in boss 94 of the platform 88. In thi manner oscillating motion is imparted to the above mentioned platform.

Platform 88- is also provided with a hub 88a pivotally mounted on the upper end of an upright spindle 88b supported in a bracket 880 carried by plate 11. Pinion 10 also drives a gear 05 mounted on shaft 98 turning in bearings of covers 91 which close the ends of inlet valve hous-' ing 98. This housing is provided with an intake 99 admitting the tobacco to the inlet valve 01 and an outlet I atits base permitting the tobacco to be delivered to the uppermost table of the drying and cooling device. The hub of the inlet valve is fastened on shaft 96, and has formed thereon spaced ribs IOI into which are fastened plates I02 closely fitting the surface of bore I03 of the valve housing. This arrangement ofthe valve construction tends to reduce to a minimum the possibility of warm air escaping from the drying chamber.

At its other end, shaft 14 is provided with a sprocket I05 driving a chain I06 running over a sprocket I01 mounted on shaft I08 carried by brackets I09 fastened on the standards IIO of the machine. A beater III fastened to shaft I00 tends to remove tobacco dust and particles of tobacco which may cling to the conveyor E,

The tobacco has now been deposited from the inlet valve on to the uppermost vibrating table I I 5 (Fig. 1) which carries a sieve I I6 (Fig. 8) and the motion of the table thoroughly agitates the tobacco to permit the sand and grit to escape through the sieve, and being lengthwise in direction feeds the tobacco on to the next table Ilia and thence on to the tables SD and H50 successively. As the tobacco is delivered from one table to the other, it'is tumbled over more or less, which has been found important because it assures uniform drying of the tobacco. Table II5 (Figs. 8 and 9) is rectangular in shape and supports the sieve 6, which may be a perforated sheet having stamped holes of about mm. diameter, permitting the passage of heated air without loss of tobacco. The table H5 is fastened to side plates II1 (Figs. 1 and 2) attached to channels II8 which may be vibrated lengthwise from a Eureka-Buhler eccentricless drive II9, such as shown in the patent to Roth, 1,517,587. The driven gyratory member thereof is attached to a cross member I supported by angle-irons I 2| provided on each of the channels II8. Amotor I22 (Figs. 1, 6 and 7) mounted tables and their sieves.

notched to provide a toothed surface, and alternate teeth thereof are upturned to provide lips I31a (Fig. 10). A yieldable element I42 provided with a toothed edge I43 cooperates with the forward end of each shaker plate to break up any lumps and feed down onto the next sieve more uniformly, Member I42 is mounted on a pintle I44 and counter-balanced by a weight I45 which is adjust'ably mounted on member I42 to hold the same closer or farther away from the end of plate I31 in order to break up the lumps of tobacco most efflcaciously.

From the foregoing, it will be clear that the invention consists in part of the combination with a shredder adapted to separate slices from a compressed mass of tobacco, and to forward said individual slices transversely of their length while so separated and loosening their shreds, of mechanism for advancing sai'd loosened slices successively in the direction of their length and thereby spreading the slices, a drier, and mechanism for transferring the loosened shreds to said drier forming a mat of opened shreds substantially continuous and uniform in depth an breadth.

It is further apparent-from the foregoing disclosure that the invention includes a drier-mechanism D comprising in a unitary structure means I50-I50 for drying the shredded tobacco, mechanism I5--I6 for advancing the individual slices 'transversely of their length while separated,

springs at their bases being anchored to station-' ary channels I21 supported on beds I28. A pair of cross-bars I (Figs; 8 and 9) attached to the to one end of bell on shaft I34., .'I h 10th connected by 1.

are pivotallyim brackets I30 mo I and MI. The pla es.

slots I I1a permitting movementof the same over the rods I34, I.,4 0 "and .4 :The latter are fixed at their ends infsock I4Ia carried by the frame work of the machine. .Itwill be seen that the to and .fro motionof tables II5, II5a-and II5b permits the bearings I3I 'to actuate links I32, whereby levers I 33 are-rocked to impart reciprocating motion to the shaker tables I31, thereby delivering to the succeeding sieve. The forward end of each of the shaker plates I31is suitably means B to then advance them successively in the direction of their length, thereby spreading the slices of tobacco lengthwise, and mechanism E, I02 for transferring them to said drier-mechanism, forming thereon a mat of open shreds substantially continuous and uniform in depth and breadth.

The invention also includes, as above disclosed, mechanism I31 for disintegrating said mat continuously and uniformly to constitute a continuous stream of fluffy shreds, and a unitary mechanism I53 for spreading, drying and cooling said stream, and means I54 for delivering the supply of filler tobacco constituted thereby.

The air for drying the tobacco may be heated by a steam heated radiator I0 arranged in the air intake I of the machine (Fig. 1), and the ;warm air is drawn out at the top of the chamber "through ducts I5I of a conduit I52 leading to a {suitable source of suction such as a fan or the 1 like; The tables are provided with batiie plates I53 which prevent the warm air from circulating out underneath the shaker plates I 31. Therefore the current of warm air i directed underneath the vibrating tables and drawn upwardly through v the perforations ofthe sieves and dries the to- ':;';bacco thereon. A humidostat (not shown) may bearranged within the drier to control a shutter) or valve in the air intake and govern the flow of air. The tables I I5, I I 5a and H51) each deliver to the succeeding table, and the last table 50, having no shaker plate, delivers the shredded tobacco directly into a discharge valve ;65'

I54, which dumps the tobacco into a truck T.

.A bailie plate I 55 prevents th warm air from flowing under the forward end of the table 50 and in a sense provides a cooling compartment or chamber. The latter chamber is equipped with a shutter I56 fixed on a shaft I51 with a handwheel I58 providing means for regulating the cool air inlet to best suit the requirements for proper cooling of the tobacco.

The channels I21 support a number of U- shaped frames I60serving to carry the side, top

and end heat insulating boards ltl, and also the outer shell I02 of the machine, as shown in Figs. 1 and 2.

The humidostat (not shown) is arranged within the drying chamber to close a circuit through a solenoid and thereby open a shutter and admit cool air to its airintake I50 whenever the humidity within the drying chamber falls below a predetermined degree. As shown more particularly in Fig, 11, the solenoid circuit includes the leads 200 of the winding of the solenoid 20i whose core is linked to the arm 202 pivoted on the bracket 203.

A tension spring 204 normally holds the shutter-205 carried by armc202 in position to cut oi! the supply of cool air to the air intake I50. If desired, the shutter 205 may be provided with felt strips 206 at the margin or its inner face which engage the margins of the cool air inlet 201 provided in the bottom i50a of the air intake and interrupt the ingress of cool air therethrough, unless the solenoid is actuated by the humidostat and the shutter is thereby opened.

" The agitation of the tobacco on the sieves, together with the tumbling thereof from one vibratory table to another assures a more eflicient removal of the dust in the upward current of warm air through the sieves and thence out 01' the machine, Heretofore, for this purpose, the shredded tobacco was subjected to a current of cool air during the cooling operation, but the re-'- moval of dust in this manner was inefllcient.

. What is claimed is:

1. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco, of a drier, mechanism for rolling the slices and thereby loosening the shreds of tobacco in the slices separated by said shredder and transporting them to said drier.

2. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco, of a drier, mechanism for loos ening the shreds of tobacco in the slices separated by said shredder and transporting them to said drier, said mechanism including a pair of members having relative movement and coacting to roll a slice therebetween, and a device for transferring the slices from said shredder to said members whereby the slices are rolled between said members and the shreds thereof are thereby loosened.

3. The combination with a guillotine shredder adapted to separate slices from a compresse mass of tobacco, of a drier, and mechanism for loosening the shreds of tobacco in the slices sep arated by said shredder and transporting them to said drier, said mechanism including sets or members having relative movement and coacting to roll the slices therebetween first in one direction and then the other,'and a device for transferring slices from said shredder to said members, whereby the compressed shreds of the slices will be loosened by being so rolled in one direction and then rolled in the opposite direc-' tion.

4. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco, of a drier, and mechanism for rolling the slices and thereby loosening the shreds oi tobacco in the slices separated by said shredder and transporting them to said drier, said drier including a series of vibratory sieves arranged in cascade relation and adapted to agitate the tobacco thereon to permit dust-and grit to escape therefrom through the sieve, and feed the tobacco on to the next sieve, whereby the to- .bacco is tumbled while being delivered from one sieve to the next, means for circulating warm air through the sieves'to dry the tobacco thereon, and means to cool the warm tobacco shreds.

5. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco, of a drier, and mechanism for loosening the shreds of tobacco in the slices separated by said shredder and transporting them to said drier, inclined vibrating shaker tablesintermediate adjacent sievesand arranged toereceive tobacco from one sieve and deposit it upon the next sieve, and memberscoacting with the delivery end of each shaker table to loosen any lumps of tobacco thereon.

6. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco, of mechanism for rolling and thereby loosening the shreds of tobacco in the slices separated by said shredder.

7. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco, of mechanism for loosening the shreds of tobacco in the slices separated by said shredder, said mechanism including members having relative movementand coacting to roll a slice of tobacco therebetween.

8. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco, of mechanism for loosening the shreds of tobacco in the slices separated by said shredder, said mechanism including a revolving member, a flexible element yieldingly held against said member, and a device for transferring the slices from said shredder on to said member whereby the slices are rolled between said element and member and the shreds thereof are thereby loosened.

9. The combination with a guillotine shredder adapted to separate slices from a compressed mass of tobacco. of mechanism for loosening the shreds of tobacco in the slices separated by said shredder, said mechanism including a pair of oppositely revolving members. a pair of oppositely arranged elements yieldingly held against opposite sides of said members respectively, and a device for, transferring slices from said shredder on to one of said members, the other of said members being arranged to receive the slices from the first member, whereby the compressed shreds of the slices will be loosened by being rolled in one direction between the first member and its yielding element and then rolled in the opposite direction between the second member and its yielding element.

10. Mechanism for loosening the shreds of tobacco in slices separated from a compressed mass or tobacco, comprising opposed members spaced suiilciently to admit a slice of tobacco therebetween and having suflicient relative movement to effect rolling of the slice whereby the shreds thereof are thereby loosened.

11. Mechanism for loosening the shreds of slices of tobacco separated from a compressed mass, comprising sets of members having relative movement and coacting to roll a slice of tobacco first in one direction and then the other whereby the shreds thereof are loosened.

12. The Process of preparing tobacco which comprises the steps of separating slices from a compressed mass of tobacco, rolling the slices individually to loosen the shreds of tobacco in the slices, and drying the shreds.

13. The process of preparing tobacco which comprises the steps of cutting slices from a compressed mass of tobacco, and rolling the slices individually between endless travelling membersone of which has differential movement of its slice-engaging surface relatively to that of the other.

14. The process of preparing tobacco as claimed in claim 13, and in which one of said members is constituted by an endless flexible band operating in a constantly forward direction.

15. The combination with a shredderadapted to separate slices from a compressed massof tobacco, of a drier-mechanism, comprising in a unitary structure means for drying, flufllng and cooling the shredded tobacco, mechanism to advance the individual slices transversely of'their length while separated, and then to advance them successively in the direction of their length, thereby spreading the slices of tobacco lengthwise, and mechanism for transferring. them to said drier-mechanism, forming therein a mat of opened shreds substantially continuous and uniform in depth and breadth.

16'. The combination with a shredder adapted to separate slices from a compressed mass of tobacco, and to forward said individual slices transversely of their length while so separated and to loosen their shreds, mechanism for advancing said loosened slices successively in the direction of their length and thereby spreading the slices,

a drier, and mechanism for transferring the loosened shreds to said drier forming a mat 0! opened shreds substantially continuous and uniform in depth and breadth.

1'7. The combination with a shredder adapted to separate slices from a compressed mass of tobacco, of mechanism to advance the individual slices transversely of their length while separated, and then to advance them successively in the direction of the length, thereby spreading the slices lengthwise in a mat substantially continuous and uniform in depth and breadth while preserving substantially the original continuity of the shred lengths.

18 The combination with a shredder adapted to separate slices from a compressed mass of tobacco, of mechanism to advance the individual slices transversely of their length while separated, thereby spreading the slices lengthwise in approximate continuity of the shred lengths, loosening the shreds thereof, to free the included foreign substances, such as grit, and forming a mat of shredded tobacco substantially continuous and uniform in depth and breadth, mechanism for disintegrating said mat continuously and uniformly to constitute a continuous stream of fluffy shreds, and a unitary mechanism for spreading, drying and cooling said stream,and for delivering the supply of filler tobacco constituted thereby.

ROSS V. CRAGGS. 

